Date of Award

2008

Publication Type

Doctoral Thesis

Degree Name

Ph.D.

Department

Chemistry and Biochemistry

First Advisor

Doug Stephan

Keywords

Pure sciences, Hafnium, Lewis acids, Phosphinimide, Titanium

Rights

info:eu-repo/semantics/openAccess

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

Abstract

The study of the chemistry of phosphinimine incorporating a Lewis acid fragment has been investigated. These compounds form stable heterocycles containing P-N-B-C elements such as [(C6F5)2BCH 2]t-Bu2PNSiMe3 as evidenced by X-ray crystallography.

The syntheses of linked (phosphinimide-cyclopentadienyl) complexes of titanium have been achieved using olefin metathesis. These compounds exhibited high activity in olefin polymerization when activated with MAO or B containing activators. Other titanium complexes containing linked ( bis-phosphinimide) ligands and non-linked ligands have been prepared as well. Based on polymerization testing, the link shows no effect on activity.

The chemistry of phosphinimide complexes of hafnium has been studied. A few complexes were prepared having one, two and three phosphinimide ligands. When cyclopentadienyl ligand was introduced, ligand disproportionation has been observed. Only sterically bulky cyclopentadienyl groups form stable complexes. The reactivity of some compounds toward Lewis acids such as B(C6F 5)3 or HB(C6F5)2 as well as ethylene polymerization testing have been explored.

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